Peptostreptococcus anaerobius: Pathogenicity, identification, and antimicrobial susceptibility. Review of monobacterial infections and addition of a case of urinary tract infection directly identified from a urine sample by MALDI-TOF MS.

Peptostreptococcus anaerobius is a gram-positive anaerobic coccus (GPAC) found in the gastrointestinal and vaginal microbiota. The organism is mainly found in polymicrobial and scarcely in monobacterial infections such as prosthetic and native endocarditis. Anaerobic bacteria have rarely been reported as the cause of urinary tract infection (UTI). Although GPAC are susceptible to most antimicrobials used against anaerobic infections, P. anaerobius has shown to be more resistant. Herein, we report a case of UTI caused by P. anaerobius from a 62-year-old man with a history of urological disease. Surprisingly, the microorganism was directly identified by Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) from the urine sample. The isolate was successfully identified by phenotypic methods, MALDI-TOF MS, and 16S rRNA gene sequencing. P. anaerobius showed no ß-lactamase-producing activity, was resistant to penicillin, ampicillin, ciprofloxacin and levofloxacin, and displayed intermediate susceptibility to ampicillin-sulbactam and amoxicillin-clavulanic acid. Successful treatment was achieved with oral amoxicillin-clavulanic acid. Antimicrobial susceptibility testing (AST) should be performed on P. anaerobius isolates due to their unpredictable AST patterns and because empirically administered antimicrobial agents may not be active. This report shows that MALDI-TOF MS, directly used in urine specimens, may be a quick option to diagnose UTI caused by P. anaerobius or other anaerobic bacteria. This review is a compilation of monobacterial infections caused by P. anaerobius published in the literature, their pathogenicity, identification, and data about the antimicrobial susceptibility of P. anaerobius.

Experimental autoimmune encephalomyelitis is associated with changes of the microbiota composition in the gastrointestinal tract.

The gut microbiome is known to be sensitive to changes in the immune system, especially during autoimmune diseases such as Multiple Sclerosis (MS). Our study examines the changes to the gut microbiome that occur during experimental autoimmune encephalomyelitis (EAE), an animal model for MS. We collected fecal samples at key stages of EAE progression and quantified microbial abundances with 16S V3-V4 amplicon sequencing. Our analysis of the data suggests that the abundance of commensal Lactobacillaceae decreases during EAE while other commensal populations belonging to the Clostridiaceae, Ruminococcaceae, and Peptostreptococcaceae families expand. Community analysis with microbial co-occurrence networks points to these three expanding taxa as potential mediators of gut microbiome dysbiosis. We also employed PICRUSt2 to impute MetaCyc Enzyme Consortium (EC) pathway abundances from the original microbial abundance data. From this analysis, we found that a number of imputed EC pathways responsible for the production of immunomodulatory compounds appear to be enriched in mice undergoing EAE. Our analysis and interpretation of results provides a detailed picture of the changes to the gut microbiome that are occurring throughout the course of EAE disease progression and helps to evaluate EAE as a viable model for gut dysbiosis in MS patients.

ent-Copalic acid antibacterial and anti-biofilm properties against Actinomyces naeslundii and Peptostreptococcus anaerobius.

Diterpenes are an important class of plant metabolites that can be used in the search for new antibacterial agents. ent-Copalic acid (CA), the major diterpene in Copaifera species exudates, displays several pharmacological properties. This study evaluates the CA antibacterial potential against the anaerobic bacteria Peptostreptococcus anaerobius and Actinomyces naeslundii. Antimicrobial assays included time-kill and biofilm inhibition and eradication assays. Time-kill assays conducted for CA concentrations between 6.25 and 12.5 µg/mL evidenced bactericidal activity within 72 h. CA combined with chlorhexidine dihydrochloride (CHD) exhibited bactericidal action against P. anaerobius within 6 h of incubation. As for A. naeslundii, the same combination reduced the number of microorganisms by over 3 log10 at 24 h and exerted a bactericidal effect at 48 h of incubation. CA at 500 and 2000 µg/mL inhibited P. anaerobius and A. naeslundii biofilm formation by at least 50%, respectively. CA at 62.5 and 1.000 µg/mL eradicated 99.9% of pre-formed P. anaerobius and A. naeslundii biofilms, respectively. These results indicated that CA presents in vitro antibacterial activity and is a potential biofilm inhibitory agent. This diterpene may play an important role in the search for novel sources of agents that can act against anaerobic bacteria.

Effect of smokeless tobacco products on human oral bacteria growth and viability.

To evaluate the toxicity of smokeless tobacco products (STPs) on oral bacteria, seven smokeless tobacco aqueous extracts (STAEs) from major brands of STPs and three tobacco-specific N-nitrosamines (TSNAs) were used in a growth and viability test against 38 oral bacterial species or subspecies. All seven STAEs showed concentration-dependent effects on the growth and viability of tested oral bacteria under anaerobic culture conditions, although there were strain-to-strain variations. In the presence of 1 mg/ml STAEs, the growth of 4 strains decreased over 0.32-2.14 log10 fold, while 14 strains demonstrated enhanced growth of 0.3-1.76 log10 fold, and the growth of 21 strains was not significantly affected. In the presence of 10 mg/ml STAEs, the growth of 17 strains was inhibited 0.3-2.11 log10 fold, 18 strains showed enhanced growth of 0.3-0.97 log10 fold, and 4 strains were not significantly affected. In the presence of 50 mg/ml STAEs, the growth of 32 strains was inhibited 0.3-2.96 log10 fold, 8 strains showed enhanced growth of 0.3-1.0 log10 fold, and 2 strains were not significantly affected. All seven STAEs could promote the growth of 4 bacterial strains, including Eubacterium nodatum, Peptostreptococcus micros, Streptococcus anginosus, and Streptococcus constellatus. Exposure to STAEs modulated the viability of some bacterial strains, with 21.1-66.5% decrease for 4 strains at 1 mg/ml, 20.3-85.7% decrease for 10 strains at 10 mg/ml, 20.0-93.3% decrease for 27 strains at 50 mg/ml, and no significant effect for 11 strains at up to 50 mg/ml. STAEs from snuffs inhibited more tested bacterial strains than those from snus indicating that the snuffs may be more toxic to the oral bacteria than snus. For TSNAs, cell growth and viability of 34 tested strains were not significantly affected at up to 100 µg/ml; while the growth of P. micros was enhanced 0.31-0.54 log10 fold; the growth of Veillonella parvula was repressed 0.33-0.36 log10 fold; and the cell viabilities of 2 strains decreased 56.6-69.9%. The results demonstrate that STAEs affected the growth of some types of oral bacteria, which may affect the healthy ecological balance of oral bacteria in humans. On the other hand, TSNAs did not significantly affect the growth of the oral bacteria.

Assessment of the antibacterial, cytotoxic and mutagenic potential of the phenolic-rich hydroalcoholic extract from Copaifera trapezifolia Hayne leaves.

Copaifera trapezifolia Hayne occurs in the Atlantic Rainforest, which is considered one of the most important and endangered tropical forests on the planet. Although literature works have described many Copaifera spp., their biological activities remain little known. In the present study, we aimed to evaluate (1) the potential of the hydroalcoholic extract from C. trapezifolia leaves (CTE) to act against the causative agents of tooth decay and apical periodontitis and (2) the cytotoxicity and mutagenicity of CTE to ensure that it is safe for subsequent application. Concerning the tested bacteria, the MIC and the minimum bactericidal concentration of CTE varied between 100 and 400 µg ml-1. The time-kill assay conducted at a CTE concentration of 100 µg ml-1 evidenced bactericidal activity against Porphyromonas gingivalis (ATCC 33277) and Peptostreptococcus micros (clinical isolate) within 72 h. CTE at 200 µg ml-1 inhibited Porphyromonas gingivalis and Peptostreptococcus micros biofilm formation by at least 50 %. A combination of CTE with chlorhexidine dichlorohydrate did not prompt any synergistic effects. The colony-forming assay conducted on V79 cells showed that CTE was cytotoxic at concentrations above 156 µg ml-1. CTE exerted mutagenic effect on V79 cells, but the micronucleus test conducted on Swiss mice and the Ames test did not reveal any mutagenicity. Therefore, the use of standardized and safe extracts could be an important strategy to develop novel oral care products with antibacterial action. These extracts could also serve as a source of compounds for the discovery of new promising biomolecules.

First case of infectious endocarditis caused by Parvimonas micra.

P. micra is an anaerobic Gram-positive cocci, and a known commensal organism of the human oral cavity and gastrointestinal tract. Although it has been classically described in association with endodontic disease and peritonsillar infection, recent reports have highlighted the role of P. micra as the primary pathogen in the setting of invasive infections. In its most recent taxonomic classification, P. micra has never been reported causing infectious endocarditis in humans. Here, we describe a 71 year-old man who developed severe native valve endocarditis complicated by aortic valvular destruction and perivalvular abscess, requiring emergent surgical intervention. Molecular sequencing enabled identification of P. micra.

Beta-lactamic resistance profiles in Porphyromonas, Prevotella, and Parvimonas species isolated from acute endodontic infections.

INTRODUCTION: Susceptibility to beta-lactamic agents has changed among anaerobic isolates from acute endodontic infections. The aim of the present study was to determine the prevalence of the cfxA/cfxA2 gene in Prevotella spp., Porphyromonas spp., and Parviomonas micra strains and show its phenotypic expression. METHODS: Root canal samples from teeth with acute endodontic infections were collected and Porphyromonas, Prevotella, and Parvimonas micra strains were isolated and microbiologically identified with conventional culture techniques. The susceptibility of the isolates was determined by the minimum inhibitory concentration of benzylpenicillin, amoxicillin, and amoxicillin + clavulanate using the E-test method (AB BIODISK, Solna, Sweden). The presence of the cfxA/cfxA2 gene was determined through primer-specific polymerase chain reaction. The nitrocefin test was used to determine the expression of the lactamase enzyme. RESULTS: Prevotella disiens, Prevotella oralis, Porphyromonas gingivalis, and P. micra strains were susceptible to benzylpenicillin, amoxicillin, and amoxicillin + clavulanate. The cfxA/cfxA2 gene was detected in 2 of 29 isolates (6.9%). Simultaneous detection of the cfxA/cfxA2 gene and lactamase production was observed for 1 Prevotella buccalis strain. The gene was in 1 P. micra strain but was not expressed. Three strains were positive for lactamase production, but the cfxA/cfxA2 gene was not detected through polymerase chain reaction. CONCLUSIONS: There is a low prevalence of the cfxA/cfxA2 gene and its expression in Porphyromonas spp., Prevotella spp., and P. micra strains isolated from acute endodontic infections. Genetic and phenotypic screening must be performed simultaneously to best describe additional mechanisms involved in lactamic resistance for strict anaerobes.

Peptostreptococcus canis sp. nov., isolated from subgingival plaque from canine oral cavity.

A polyphasic taxonomic study was performed on two strains of an unknown Gram-positive, asaccharolytic, nonspore-forming, obligately anaerobic coccus-shaped bacterium isolated from oral subgingival plaque of Labrador retriever dogs. Comparative 16S rRNA gene sequencing confirmed that these isolates were highly related to each other and formed a hitherto unknown linage within the clostridial rRNA XI cluster of organisms. Pairwise analysis demonstrated that the novel organism to be most closely related to members of the genus Peptostreptococcus with 16S rDNA gene sequence similarity values between 92.8% and 96.7%, respectively. The G + C DNA base composition was 30.8 mol% and the major cellular fatty acids included iso-C(14:0,) iso-C(16:0), and iso-C(16:0 DMA). Based on biochemical, chemotaxonomic, and phylogenetic evidence it is proposed that the unknown bacterium be classified as a new species, Peptostreptococcus canis sp. nov. The type strain is CCUG 57081(T).

Finegoldia magna (formerly Peptostreptococcus magnus): an overlooked etiology for toxic shock syndrome?

Finegoldia magna is an anaerobic Gram positive coccus, previously classified as Peptostreoptococcus magnus. It is normal flora of the gastrointestinal and genitourinary tract, and can be isolated from skin and the oral cavity and is often regarded as a contaminant in cultures. As the most frequently isolated anaerobic coccus, it is implicated in a range of mono- and polymicrobial infections, including skin and skin structure, bone and joint (native and prosthetic joints), infective endocarditis (native and prosthetic valves), necrotizing pneumonia, mediastinitis and meningitis. Recently, whole genome sequencing furthered the understanding of the pathogenicity of this organism by elucidating both chromosomally encoded and mobile plasmid mediated virulence factors. Although no cases of toxic shock syndrome have been attributed to F. magna, we present a case of a fatal monomicrobial F. magna bacteremia and hypothesize that superantigen activity, mediated via Protein L binding the variable domain of the κ light chains of IgG, resulted in the syndrome observed in our patient. Additionally, we suspect the overall significance of this pathogen is underestimated and with more sensitive detection methods, this organism will be identified more frequently in clinical cultures and associated with true infection.

Perioperative, postoperative, and prophylactic use of antibiotics in alloplastic total temporomandibular joint replacement surgery: a survey and preliminary guidelines.

PURPOSE: In 2009, the American Academy Of Orthopedic Surgeons recommended lifelong prophylaxis after orthopedic total joint replacement (TJR) before these patients undergo dental, aerodigestive, genitourinary (GU), and gastrointestinal (GI) procedures. Because oral and maxillofacial surgeons worldwide are implanting alloplastic total temporomandibular joint replacements (TMJ TJRs), it appeared reasonable to survey these surgeons to obtain data that might shed some light, not only on this issue, but also to obtain some data to begin to develop preliminary guidelines for the peri- and postoperative use of antibiotics for TMJ TJR using these results and the orthopedic data. MATERIALS AND METHODS: A total of 35 surgeons worldwide, members of either the TMJ Concepts or Biomet Microfixation online networks were e-mailed a standard questionnaire surveying their perioperative, postoperative, and prophylactic use of antibiotics for their TMJ TJR cases. RESULTS: Of the 35 surgeons, 26 (74.2%) from 8 different countries responded. A total of 2,476 cases (3,368 joints) were retrospectively surveyed. Of the responding surgeons, 96.2% used, in order of frequency, cefazolin, clindamycin, cephalosporin, or penicillin-based antibiotics in the perioperative period and continued their use for a mean of 7 days (range 5 to 14) postoperatively. Also, 46.2% soaked the TJR components either in the perioperative antibiotic or in vancomycin, poviodine, gentamycin, or peroxide before implantation. In addition, 61.5% irrigated the wounds after device implantation with bacitracin, vancomycin, poviodine, peroxide, or the perioperative antibiotic. These surgeons reported that 51 joints (1.51%) had become infected within a mean of 6 months (range 2 weeks to 12 years) postoperatively. A total of 32 devices (0.95%) required removal and/or replacement. In cases in which the organisms were isolated, the organisms commonly associated with biofilm infection of TJR devices, Staphylococcus aureus, S epidermidis, Peptostreptococcus, and Pseudamonas aeruginosa, were cultured. In only 1 joint (0.003%) was there a suggestion of an association with an invasive dental/aerodigestive, GU/GI procedure. Regarding prophylaxis after TMJ TJRs and before dental/aerodigestive, GU, or GI procedures, 53.8% of the respondents reported that they provided prophylaxis. Of these, 1 recommended doing this for 6 months and 4 for 2 years, such as has been the American Dental Association/American Academy of Orthopedic Surgeons recommendation since 2003; and 9 reported they believe these TMJ TJR patients should have lifetime antibiotic prophylaxis before invasive dental/aerodigestive, GU, or GI procedures. CONCLUSION: The evidence provided from the present small study survey and a review of the orthopedic data could provide the opportunity to develop guidelines for the preoperative, intraoperative, and postoperative antibiotic management for TMJ TJRs and spur additional research into this important area of patient management.

Competition between yogurt probiotics and periodontal pathogens in vitro.

OBJECTIVE: To investigate the competition between probiotics in bio-yogurt and periodontal pathogens in vitro. MATERIAL AND METHODS: The antimicrobial activity of bio-yogurt was studied by agar diffusion assays, using eight species of putative periodontal pathogens and a 'protective bacteria' as indicator strains. Four probiotic bacterial species (Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, and Bifidobacterium) were isolated from yogurt and used to rate the competitive exclusion between probiotics and periodontal pathogens. RESULTS: Fresh yogurt inhibited all the periodontal pathogens included in this work, showing inhibition zones ranging from 9.3 (standard deviation 0.6) mm to 17.3 (standard deviation 1.7) mm, whereas heat-treated yogurt showed lower antimicrobial activity. In addition, neither fresh yogurt nor heat-treated yogurt inhibited the 'protective bacteria', Streptococcus sanguinis. The competition between yogurt probiotics and periodontal pathogens depended on the sequence of inoculation. When probiotics were inoculated first, Bifidobacterium inhibited Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas circumdentaria, and Prevotella nigrescens; L. acidophilus inhibited P. gingivalis, A. actinomycetemcomitans, P. circumdentaria, P. nigrescens, and Peptostreptococcus anaerobius; L. bulgaricus inhibited P. gingivalis, A. actinomycetemcomitans, and P. nigrescens; and S. thermophilus inhibited P. gingivalis, F. nucleatum, and P. nigrescens. However, their antimicrobial properties were reduced when both species (probiotics and periodontal pathogens) were inoculated simultaneously. When periodontal pathogens were inoculated first, Prevotella intermedia inhibited Bifidobacterium and S. thermophilus. CONCLUSIONS: The results demonstrated that bio-yogurt and the probiotics that it contains are capable of inhibiting specific periodontal pathogens but have no effect on the periodontal protective bacteria.

Cephalosporins in overcoming beta-lactamase-producing bacteria and preservation of the interfering bacteria in the treatment of otitis, sinusitis and tonsillitis.

The treatment of upper respiratory tract infections (URTIs) is complicated by the resurgence of beta-lactamase-producing bacteria (BLPB) and the absence of interfering bacteria. BLPB can have a direct pathogenic impact in causing the infection as well as an indirect impact through their ability to produce the enzyme beta-lactamase. BLPB may not only survive penicillin therapy but can also protect other penicillin-susceptible bacteria from penicillin. In this review, the clinical in vitro and in vivo evidence supporting the role of these organisms in the increased failure rate of penicillin in eradication of otitis, sinusitis and pharyngo-tonsillitis is outlined and the implication of that increased rate on the management of infections is discussed. Bacteria with interference capability of potential respiratory pathogens can prevent colonization and subsequent invasion by these organisms. These include alpha-hemolytic streptococci, nonhemolytic streptococci and Prevotella and Peptostreptococcus spp. Treatment with antimicrobials can affect the balance between the interfering organisms and potential pathogens. The role of bacterial interference in URTIs and its effect on their treatment is discussed. The use of some of the cephalosporins that are able to overcome the effect of BLPB and preserve the beneficial interfering bacteria can overcome and modulate these phenomena and achieve better cure of URTIs.

Comparison of growth and susceptibility to sodium hypochlorite of mono- and dual-species biofilms of Fusobacterium nucleatum and Peptostreptococcus (micromonas) micros.

This study compared growth and susceptibility to different concentrations of sodium hypochlorite (NaOCl) of mono- and dual-species biofilms of Fusobacterium nucleatum or Peptostreptococcus micros in vitro at 24 hours or 96 hours. A Mann-Whitney U test revealed that although at 24 hours dual-species biofilms had similar viable counts to those of monospecies biofilms (p > 0.001), they were more resistant to NaOCl (p < 0.001). At 96 hours, both microorganisms had higher viable counts and were more resistant to NaOCl in dual-species biofilms than in monospecies biofilms of the same microorganism (p < 0.001). As the age of the biofilms increased, so did their resistance to NaOCl. Mixed-species biofilms of F. nucleatum and P. micros showed a time-dependent synergy in growth and resistance to NaOCl.

Coaggregation interactions between oral and endodontic Enterococcus faecalis and bacterial species isolated from persistent apical periodontitis.

Interactions between Enterococcus faecalis and other species found in root canal infections might be important for the development and persistence of periapical disease. The aim of this study was to investigate the coaggregation interactions between E. faecalis clinical isolates and species previously shown to survive and induce apical periodontitis in monkeys: Peptostreptococcus anaerobius, Prevotella oralis, Fusobacterium nucleatum, and Streptococcus anginosus. Intergeneric coaggregation assays were conducted in duplicate with observations scored immediately at 0 h, 1 h and 24 h after mixing of combinations of strains. All E. faecalis strains (n = 53) coaggregated with F. nucleatum; E. faecalis did not coaggregate with P. anaerobius or S. anginosus. One strain, E. faecalis E1, coaggregated with P. oralis, with aggregates visible at 1 h. Coaggregation interactions between E. faecalis and F. nucleatum observed in this study suggest a potential role for this combination in endodontic infections.

Influence of residual bacteria on periapical tissue healing after chemomechanical treatment and root filling of experimentally infected monkey teeth.

The purpose of this study was twofold: first, to determine the influence on the healing of the periapical tissues when selected bacterial strains and combinations thereof remain after root canal treatment; and, second, the relationship to healing of the quality of the root filling. In eight monkeys, 175 root canals, previously infected with combinations of four or five bacterial strains and with radiographically verified apical periodontitis, were endodontically treated, bacteriologically controlled, and permanently obturated. After 2-2.5 yr, the periapical regions were radiographically and histologically examined. Of these teeth, 48 root canals were also examined for bacteria remaining after removal of the root fillings. When bacteria remained after the endodontic treatment, 79% of the root canals showed non-healed periapical lesions, compared with 28% where no bacteria were found. Combinations of residual bacterial species were more frequently related to non-healed lesions than were single strains. When no bacteria remained, healing occurred independently of the quality of the root filling. In contrast, when bacteria remained, there was a greater correlation with non-healing in poor-quality root fillings than in technically well-performed fillings. In root canals where bacteria were found after removal of the root filling, 97% had not healed, compared with 18% for those root canals with no bacteria detected. The present study demonstrates the importance of obtaining a bacteria-free root canal system before permanent root filling in order to achieve optimal healing conditions for the periapical tissues.

Contribution of proteases and plasmin-acquired activity in migration of Peptostreptococcus micros through a reconstituted basement membrane.

BACKGROUND/AIMS: Peptostreptococcus micros is a gram-positive bacterium that has been associated with chronic periodontitis and endodontic infections. The aims of this study were to investigate the production of proteases and the acquisition of plasmin activity by rough and smooth morphotypes of P. micros. The contribution of these properties in the migration of bacteria through a reconstituted basement membrane was also evaluated. METHODS: Protease activities were determined using chromogenic and fluorogenic substrates as well as by zymography. Plasminogen binding activity was studied using an enzyme-linked immunosorbent assay. The role of proteases and plasmin-acquired activity in tissue penetration was investigated using Matrigel. RESULTS: The rough morphotype strains of P. micros, but not the smooth morphotype strains, were found to possess chymotrypsin-like and gelatinase activities, both of which were inhibited by a serine protease inhibitor. By zymography, three gelatinase bands (165, 129, and 115 kDa) were identified. Both morphotypes of P. micros can bind human plasminogen on their cell surface. Once bound to P. micros, plasminogen activators of bacterial (streptokinase) and human (urokinase) origins were found to activate plasminogen into plasmin. Our results also showed that plasmin activity can be acquired by P. micros following co-incubation with human brain microvascular endothelial cells in culture. When non-coated cells were used, the rough morphotype strain (HG1262), which possesses chymotrypsin-like and gelatinase activities, showed a better capacity to penetrate a reconstituted basement membrane (Matrigel) than the smooth morphotype strain (HG1251). Penetration of the Matrigel by P. micros HG1262 was inhibited by the presence of a serine protease inhibitor. In addition, cells of P. micros with plasmin activity showed a significantly greater tissue penetration capacity. CONCLUSION: Our study suggests that endogenous proteolytic activities of P. micros as well as plasmin-acquired activity, may facilitate dissemination of bacterial cells to surrounding periodontal tissues and blood vessels.

Effect of mineral trioxide aggregate on cytokine production by peritoneal macrophages.

AIM: To test the effect of two commercial brands of grey mineral trioxide aggregate (ProRoot and MTA-Angelus) on cytokine production by M1 and M2 inflammatory macrophages. METHODOLOGY: M1 (from C57BL/6 mice) and M2 peritoneal inflammatory macrophages (from C57BL/6 IL12p40-/- mice) were obtained and cultured in vitro in the presence of MTA. The cellular viability and the production of tumour necrosis factor-alpha, interleukin (IL)-12 and IL-10 in response to stimulation with interferon-gamma and Fusobacterium nucleatum or Peptostreptococcus anaerobius were evaluated. Data were analysed by Mann-Whitney, Kruskal-Wallis and anova tests. RESULTS: The cements did not interfere with cellular viability or with cytokine production by either type of macrophage. However, M2 macrophages produced higher levels of IL-10 when stimulated with F. nucleatum than M1 macrophages (P < 0.05). CONCLUSIONS: The brands of MTA evaluated did not interfere in the cytokine response by M1 or M2 macrophages to the two bacteria tested. However, a difference in cytokine production between the two types of macrophages was found.

Trypanosoma cruzi: influence of predominant bacteria from indigenous digestive microbiota on experimental infection in mice.

To verify the influence of some predominant components from indigenous microbiota on systemic immunological responses during experimental Chagas disease, germ-free NIH Swiss mice were mono-associated with Escherichia coli, Enterococcus faecalis, Bacteroides vulgatus or Peptostreptococcus sp. and then infected with the Y strain of Trypanosoma cruzi. All the mono-associations predominantly induced a Th1 type of specific immune response to the infection by T. cruzi. A direct correlation was observed between a higher survival rate and increased IFN-gamma and TNF-alpha production (P<0.05) in E. faecalis-, B. vulgatus-, and Peptostreptococcus-associated mice. Moreover, higher levels of anti-T. cruzi IgG1 and anti-T. cruzi IgG2a were also found in mono-associated animals after infection. On the other hand, with the exception of E. faecalis-associated mice, mono-association induced a lower IL-10 production after infection (P<0.05) when compared with germ-free animals. Interestingly, spleen cell cultures from non-infected germ-free and mono-associated mice spontaneously produced higher levels (P<0.05) of IL-10 than cultures from infected mono-associated mice, except again for E. faecalis-associated animals. In conclusion, the presence of the components of the indigenous microbiota skews the immune response towards production of inflammatory cytokines during experimental infection with T. cruzi in gnotobiotic mice. However, the degree of increase in production of cytokines depends on each bacterial component.

Farmacocinética/farmacodinámica de la formulación de amoxicilina/ácido clavulánico 1. 000/62, 5 mg en odontoestomatología / Pharmacokinetics/pharmacodynamics of the 1000/62. 5 formulation of amoxicillin/clavulanic acid in odontostomatology

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[Biological properties of microorganisms as the basis for the prognosis of the severity of pyoinflammatory pleuropulmonary diseases]. / Biologicheskie svoistva mikroorganizmov kak osnova prognozirovaniia tiazhesti gnoino-vospalitel'nykh zabolevanii legkikh i plevry.

In the study of 65 microbial cultures isolated from the purulent foci in acute pulmonary abscess and acute pyothorax of 48 patients, a wide spectrum of microflora was detected. Staphylococci and Pseudomonas prevailed among aerobes, bacteroids and peptostreptococci--among anaerobes. In cases of the prolonged course of the pathological process, as compared with the common one, microorganisms exhibited hemolytic activity and high antilysozyme and anticomplementary levels. These findings served as the basis for working out a mathematical model for the prognosis of the disease course with 95% probability.